Core drill



De- 8, 19.31- E. A. SPENCER, .1R 1,835,189

CORE DRILL` I Filed June 19, 1928 2 Sheets-Sheet l A A Y 0 @21 i w 11 i...JJ V

lDec. '8, 1931." E. A. SPENCER, JR

CORE DRILL Filed 'Junet 19, 1928 2 Sheets-Sheet 2 Patented Dec. 8, 1931EDWARD SPENCER, JR., F LOS ANGELES, GALIFORNIA conn DRILL .Applicationled June 19,

My invention relates to core drills of the general character operated bycable tool systems in the well drilling art for obtaining a sample coreof the ground formation penetrated by the drill when in operation.

It is a purpose of my invention to provide a core drill characterized byits capability of positively maintaining the core barrel against upwarddisplacement from the ground forlo mat-ion penetrated by the core barrelso as to prevent distortion of the core being obtained and dislodgingthereof from the core barrel as the drilling' proceeds; its capabilityof aiding the upward feed of the core in the barrel l as the latterpenetrates the formation; lts

capability of preventing packing of the core in the barrel with theresultant blocking of the barrel by the core; its capability ofpreventing bending of, or other damage to the barrel by obstructions inthe hole when lowering the drill into the hole; and its vcapability ofbeing readily withdrawn from the hole even though the walls of thelatter should crumble ory cave in, to the end that the drillingoperation will be greatly facilitated and a true and accurate samplecore of the formation penetrated by the drill, obtained in,

and readily removed intact from the core ba'rrel when the drill iswithdrawn from the hole.

I will describe only one form of core drill embodying my invention andwill then point out the novel features in claims.

In the accompanying drawings.

Fig. 1 is a View showing in vertical longitudinal section one form ofcore drill embodying my invention, and illustrating the positionsoccupied by the moving parts of the drill when the latter is to belowered into a bore hole;

Fig. 2 is a view similar to Fig. 1 and showing the drill lowered into abore hole and commencing the downstroke;

.f5 Fig. 3 is a view similar to Fig. 1 and illus- 1928. serial No.286,692.

trating the downstroke of the drill as being partially completed;

Fig. 4 is a view similar to Fig. 1 and illustrating the downstroke ofthe drill as fully completed;

Fig. 5 is an enlarged detail sectional view ofda'valve structureembodied in the drill; an

Fig. 6 is a sectional view taken on the line 6--6 of Fig. 5.

Referring specifically to the drawings in which similar referencecharacters designate similar parts in each of the several views, myinvention in its present embodiment comprises a metal body .B of.cylindrical form, having an axial bore 10 extending longitudinallytherethrough, wlich'is enlarged at its lower end and threaded to receivea threaded pin 11 of a conventional form of drill bit D so as todetachably secure thebit to the body. The bit D is provided with anaxial bore 12 forming a continuation of the bore 10 of the body, and thebore '12 is reduced in diameter at the lower end of the bit as indicatedat 13,'

to provide an annular shoulder 14.

The upper end of the bore 10 of the body B is also enlarged and threadedto receive a threadedprojecti-on 1-5 on one end of a coupling pin 16,while a second threaded projection 1 7 on the other end of the pin isadapted to be Ascrewed into a conventional form of drill stem S so as tosecure the body B to the stem for reciprocation by conventionalmechanispm (not shown) in a bore hole to effect cutting and penetrationof the formation in the hole by the bit D as is well known in the artand will be understood.

Within the bores 10 and 12 is mounted for sliding movement relatively tothe body B a core barrel C having its lower end provided with aconventional form of core shoe 18. In the present instance the upper endof the vcore barrel is provided with a valve structure comprising anopen ended tubular member 19 of the same diameter as the core barrel,the

member 19 forming a continuation of the upper end of the core barrel andbeing secured thereto by a coupling collar 2O which also serves to clampa perforated disk 21 between the member and core barrel.

The member 19 is provided with a circular series of slots whichconstitute ports 22 controlled by a valve designated generally at V andcomprising an inner sleeve 23 extending freely into the upper end of themember 19, and an outer sleeve 24 freely surrounding the member 19. Theupper end of the sleeve 23 is threaded internally to receive a reduced,threaded projection 25 formed on a cap 26 having a peripheral flange 27threaded onto the sleeve 24 as indicated at 28, to the end that thesleeves and cap will be secured together to form a single unit.

The valve V is normally urged upwardly to the extreme position shown inFig. 5 wherein its sleeves 23 and 24 open the ports 22, by a coil spring29 loosely fitting within the sleeve 24 and abutting the disk 21 and theunderside of the projection 25 of the cap 26.

The uppermost position to which the valve V can be moved under theaction of the spring 29 is definitely limited by means of external andinternal iianges 30 and 31 formed on the lower ends of the sleeves 23and 24 respectively, which are adapted to abut intermal and externalfianges 32 and 33 respectively, formed on the upper end of the tubularmember 19. The valve V is adapted to be moved downwardly to the extremeposition shown in Figs. 1, 3 and 4 wherein its sleeves 23 and 24cooperate to close the ports 22, in a manner to be hereinafter fullydescribed.

The core barrel C is adapted to be driven into the formation at thebottom of a bore hole and maintained against upward displacement fromthe formation during reciprocation of the body B, b means of anoperative connection between t e body B and core barrel, which in thepresent instance comprises a coil spring 34 loosely fitting the bore 10and resting upon the cap 26; a weight 35 of cylindrical form, alsoloosely fitting the bore 10 and having at one end a reduced extension 36entering the spring 34 to prevent relative lateral displacement of theweight and spring; and a second coil spring 37 of greater strength thanthe spring 34 and loosely fitting the bore 10. The spring 37 normallyrests upon the weight 35 and receives a reduced extension 38 formed onthe opposite end of the weight so that relative lateral displacement ofthe second spring and weight is prevented.

It will be noted that a retaining member in the form of a collar 39 isthreaded into the lower end of the bore 10, and that the internaldiameter of the member is such as to freely pass the core barrel C andits valve V when it is desired to withdraw the barrel from the body Bafter removal of the bit D, yet prevents passage of the spring 34 sothat the latter as well as the weight 35 and second spring 37 areprevented from dropping out of the barrel into the bore hole or possiblyinjuring workmen.

Furthermore, the core barrel is adapted to be releasably held in theretracted position in the body B, as is shown in Fig. 1, by a shearablemeans, in the present instance comprising a pair of pins 40 of softmetal which are threaded into lugs 41 formed at diametrically opposedpoints on the underside of the bit D adjacent its bore 12, and adaptedto be tightly screwed against the core barrel, so that the core barrelwill be held in retracted position with only the lower extremity of thecore barrel and core shoe thereon projecting from the bit D. The dangerof bending or otherwise damaging the core barrel when lowering the drillinto the bore hole is thus prevented. However, when the core shoe 18strikes the formation at the bottom of the bore hole, the weight of thebody B and the drilling string imposed on the pins 40, will cause thelatter to shear off so that the core barrel will be free to move toextended position with respect to the body B.

The operation of the core drill is as follows:

Assuming that the drill has been lowered into the bore hole and that thepins 40 have been sheared off, the drill will be submerged in theiushing liquid in the hole and the liquid will be free to enter the bore10 of the body B through pressure relief ducts 42 formed in the sidewall of the body, and to enter the core barrel through the ports 22.

Reciprocation of the body B by the usual mechanism (not shown)v isinitiated, and during the downstroke of the body from the position shownin Fig. 2 flushing liquid in the bore 10 is ejected therefrom throughthe ducts 42. When the projection 15 of the coupling pin 16, whichcloses the upper end of the body,

strikes the spring 37, the valve V is moved downwardly through themedium of the weight 35 and spring 34, to cause flushing liquid in thecore barrel to be ejected therefrom into the bore 10, through the ports22 and thence out of the bore 10 through the ducts 42.l Continueddownward movement of the body B moves the valve V to its lowermostextreme position shown in Fig. 3 to thus close the ports 22, after whichthe springs 34 and 37 are compressed as shown in Fig. 4 to transmit tothe core barrel, a cushioned blow operating to drive the barrel into theformation at the bottom of the bore hole as the bit D cuts into theformation. A sample core of the formation being penetrated by the bit Dis thus forced up into the core barrel, and to prevent packing of thebarrel with the consequent blocking up of the barrel by the core, thebarrel is tapered internally to increase in diameter upwardly of thebarrel as indicated at 43.

function of exerting a downward force on the Y barrel through the mediumof the s ring 34 and valve V, the spring 37 being o greater .strengththan the spring 34 resists and overcomes the rebounding action of thelatter spring to such extent that the weight is held down inengagementwith the spring 34 so as to continue'to exert its downward force uponthe barrel. The barrel is thus held down againstupward displacement fromthe formation, so that distortion of the core being formed in the barrelor dislodging of the core from the barrel, is positively prevented, tothe end that a true and accurate sample of the formation beingpenetrated by the drill, will be obtained..

Upon continued upward movement of the body, and when sutlicient movementof the latter has been eifected to permit the springs 34 and 37 to fullyexpand, the sprlng 29.

operates under its normal urging action to move the valve V upwardly andsuddenly open the ports 22. As the pressure relief ducts 42 will notpermit a sufficient quant1ty of flushing liquid to enter and immediatelylill the bore 10 of the body and the space in the core barrel above thecore therein, as the upstroke vof the body progresses, a partial vacuumis produced in the bore and barrel during the upstroke of the Abody soas to tend to suck or draw the core upwardly in the barrel. Sticking ofthe core inthe barrel is thus prevented and the upward feed of the coregreatly facilitated. y

lt will be appreciated that the operations of the springs 34 and 37,weight 35, and valve V, as a result lof the reciprocations of the bodyB, occur very rapidly as the body 1s reciprocated at a speed ofapproximately thirty strokes per minute so that the suction isv inducedin the barrel very quickly to' act with maximum effectiveness on thecore in the barrel. Furthermore, it will be noted that the strength ofthe spring 29 is sufficient to raise the valve V, spring 34, weight 35,and spring 37 so as to maintain the valve open when the projection 15 isclear of the latter spring.

It will be clear that on the downstroke of the body B, the springs 34and 37 effectively prevent a sharp blow from being delivered againstth'e core barrel so that bending or kinking of the barrel is prevented,and the barrel driven down into the formation without undue stressthereupon, as well as positively maintained at all times during thedrilling operation against upward displacement from the formation sothat a true and accurate sample core of the formation will be recovered.

\ vLemmer) When the barrel has been driven into the formationsuiiiciently to obtain the desired length of core, the body is raisedfrom the bore hole, and during the upward movement of the body, theshoulder 14 in the bit D strikes the sleeve 24 of the valve V and thuswithdraws the core barrel from the'formation and causes the barrel toremain suspended from the body and raised therewith from the hole.

The body B is tapered exteriorly so as to increase in diameter upwardly,as is indicated at 44, which tapered form greatly facilitates withdrawalof the drill 'from the bore hole should the walls of the latter havecrumpled or caved in and-thus tend to freeze the body in the hole.

' Although I have herein shown and described ohly one form of core drillembodying my invention, it is to be understood that various changes andmodifications may be made therein without departing from the spirit ofthe invention and the spirit and scope vof the appended claims.

I claim:

1. A core drill comprising a bit carrying body adapted to be connectedto a drill stem for reciprocation thereby in a bore hole, a core barrelmounted for movement in the body and adapted to penetrate the formationin the bottom of the bore hole, means operable by the body during thedownstroke of the latter, to drive the core barrel into the formationand thereby obtain a sample core of the formation, and means forcreating a partial vacuum Iin the barrel above the core therein so as totend to suck the core upwardly inthe barrel.

2. A core drill comprising a bit carrying body adapted to be connectedto a drill stem for reciprocation thereby in a bore hole, a core barrelmounted for movement in the body and adapted to penetrate the formationinthe bottom of the bore hole, means operable by thebody during thedownstroke of the latter, to drive the core barrel into the formationand thereby obtain a sample core of the formation, and means operableupon onek stroke of the body to. eject from the barrel, iushing fluidtherein above the core, and operable upon the other stroke of the bodyto induce suction in the barrel above the core so as to tend to draw thelatter upwardly in the barrel.

`3. A core drill comprising abit carrying body adapted to be connectedto a drill stem for reciprocation thereby in-a bore hole, a core barrelmounted for movement in the body and adapted to penetrate the formationin the bottom of the bore hole, means operable by the body during thedownstroke of the latter, to'drive the core barrel into the formationand thereby obtain a sample core one stroke of the body to eject fromthe barrel, flushing fiuid therein above the core, and operable upon theother stroke of the body to induce suction in the barrel above the coreso as to tend to draw the latter upwardly in the barrel, said last meanscomprising ports in the core barrel, and a valve for controlling theports, normally urged to one position to open the ports and movable bythe first means to a second position wherein it closes the ports.

4. A core barrel having ports, and a valve mounted for movement on thecore barrel to open or close the ports according as the valve occupiesone position or another, and means for normally urging the valve to theposition wherein the1 ports are open.

5. A core barrel having ports, and a valve comprisingan inverted cupshaped element closing the upper end of the core barrel and slidablymounted on the latter to open or close the ports, according as theelement occupies one extreme position or another, and lneans for urgingthe element to one extreme position.

6. A core drill comprising a bit carrying body adapted to be connectedto a drill stem for reciprocation thereby in a bore hole, a core barrelmounted for movement in the body and adapted to penetrate the formationin the bottom of the bore hole, and a yieldable operative connectionbetween the body and core barrel by which the latter is caused to bedriven into the formation to obtain a sample core thereof, upon thedownstroke of the body, and is maintained against displacement from theformation upon the upstroke of the body, whereby distortion of the corewill be prevented and a true and accurate sample of the formation beingpenetrated, obtained, said operative connection comprising a spring inthe body engaging the upper end of the barrel, a weight resting upon thespring and adapted to exert pressure downwardly upon the barrel throughthe medium of the spring, and a second spring in the body, resting uponthe weight and adapted to be struck and compressed by the body duringthe downstroke thereof, to transmit the movement of the body to thebarrel through the medium of the weight and the first spring, saidsecond spring being of greater strength than the first spring andoperable during the upstroke of the body to prevent sudden rebounding ofthe first spring so that the weight will constantly act to hold the corebarrel down and against displacement from the formation.

7. A core drill comprising a bodyv having a bit on its lower end, thebody and bit being provided with a bore extending longitudinally andopening to the lower end of the bit, a core barrel slidably mounted inthe bore, a coil spring in the bore resting upon the upper end of thecore barrel, a weight in the bore resting upon the spring, and a seoondspring in the bore resting upon the Weight,

the second spring being of different strength than the first spring.

8. A core drill comprising a body having a bit on its lower end, the bodand bit being provided with a bore exten ing longitudinally and openingto the lower end 0f the bit, a core barrel slidably mounted in the bore,a coil s ring in the bore resting upon the up er end) of the corebarrel, a weight in the ore resting upon the spring, a second spring inthe bore resting upon the Weight, and a retaining member removablyfitted in the bore of the body, for preventing droppin of the springsand weight from the bore W en the bit is removed from the body and thebarrel withdrawn from the bore.

9. A core drill comprising a bit body. adapted for connection to a drillstem for reciprocation thereby and having a bore extendinglongitudinally therein, a core barrel slidably mounted in the bore ofthe body and having ports, a valve comprising a sleeve slidably mountedon the upper extremity of the core barrel for opening or closing saidports according as the sleeve occupies one extreme osition or the other,means for normally urgmg the sleeve to the extreme position in which theports will be open, and a yieldable operative connection 1n the bore,for moving the valve to its closed position and driving the core barrelinto ground formation during the downstroke of the body.

10. A core drill comprising a body having av bore, a core barrelslidable in the bore, a Weight in the bore, a spring in the bore betweenthe core barrel and Weight, and a second spring in the bore between theweight and body, the springs being of different strengths.

11. A core drill comprising a body having a bore, a core barbel slidablein the bore, a Weight in the bore, a spring in the bore between the corebarrel and Weight, and a second spring in the bore between the Weightand body, and being of greater strength than the first spring.

12. A core drill comprising a bit body, a core barrel mounted formovement in the body and having a port, a valve controlling the port andnormally ur ed to a position to open the port, and mea-ns or moving thevalve to a second position to close the port during the dovvnstroke ofthe body.

13. A core drill comprising a bit body, a core barrel mounted formovement in the body and having a port, a valve controlling the port andnormally urged to a position to open the port, and means for moving thevalve to a second position to close the port during the downstroke ofthe body, and driving the core barrel into ground formation during thedovvnstroke of the body.

14. A. core drill comprising a bit body, a core barrel slidable in thebody for driving by the body into ground formation during the downstrokeof the body, and means for ejecting flushing fluid from thecore barrelabove a core therein during one stroke of the y- 15.` A core drillcomprising a bit body, a

core barrel slidable in the body for driving by the body into groundformation during the downstroke of the body, and means for inducingsuction in the core barrel above a core therein during one stroke of thebody so as to tendlto barrel.

`draw the core upwardly in the Signed at Angeles, inthe oounty of LosAngeles, and State of California this 2d day of June A. D. 1928.

EDWARD ALLEN SPENCER, JR.

